1. Field of the Invention
The present invention relates to a bracket and a hydraulic valve for a height-adjustable washstand. More particularly, the present invention relates to a bracket of a height-adjustable washstand for allowing the washstand to go up and down by providing a cylinder at the bottom of the washstand, and a hydraulic valve for controlling a height of the washstand by using hydraulic pressure.
2. Description of the Related Art
As well known, because the washstand for utilizing the tap water is fixed to a wall, at a predetermined height for adult, persons larger or smaller than the height, especially, children have difficulty in using the washstand of the general adult height.
In order to solve the above problem, by establishing a cylinder which is operated by oil pressure or water pressure at the bottom of the washstand, a technology allowing the washstand to go up and down has been disclosed which is illustrated in FIG. 1, FIG. 2 and FIG. 3.
Referring to FIG. 1, a cylinder 101 which is operated by oil pressure or water pressure is provided at the bottom of the washstand 100, and a piston rod 103 of the cylinder 101 is provided on the floor. Also, the cylinder 101 is connected to a control valve 105 through pressure pipes 110, the control valve 105 comprising back-force tanks 1 and 2, 106 and 107, a valve body 108 for controlling pressure of the back-force tanks 1 and 2, 106 and 107, and a switch 109 for controlling the valve body 108.
The back-force tank 1, 106 is connected to the portion above a piston 102 in the cylinder 101, and the back-force tank 2, 107 is connected to the portion below the piston 102 in the cylinder 101. Means for supplying pressure to the back-force tanks 1 and 2, 106 and 107 may be any one of an air compressor, a hydraulic pump, and an oil pressure pump connected to the control valve 105 in accordance with kinds of the cylinder 101.
Therefore, if the valve body 108 is allowed to apply pressure to the back-force tank 1, 106 through operation of the switch 109, the pressure is transferred to the portion above the cylinder 101 from the back-force tank 1, 106. However, since the piston 102 and the piston rod 103 are fixed, and the pressure at the portion above the piston 102 in the cylinder 101 is increased, cylinder 101, the control valve 105, and the washstand 100 which is coupled to the cylinder 101 go up.
Further, if pressure is applied to the back-force tank 2, 107, the pressure is transferred to the portion below the cylinder 101 from the back-force tank 2, 107, so that the cylinder 101, the control means 105, and the washstand 100 which is coupled to the cylinder 101 go down.
In this way, the height of the washstand 100 is adjusted through operation of the control valve 105, and an impact when the washstand 100 goes up and down is absorbed and mitigated by the spring 104 provided in the cylinder 101, so that a user can properly adjust the washstand 100 to his own height.
However, because the above washstand 100 is coupled to and supported by the cylinder 101 to go up and down, there is a problem that its supported state is not stable.
In other words, since the washstand 100 is supported by the cylinder 101, and the cylinder 101 is supported by the piston rod 103, most of heavy elements such as the washstand 100, the cylinder 101, and the control valve 105 are supported by the piston rod 103 of which a sectional area is very small.
Therefore, when the washstand 100 goes up and down, it is not supported enough, and the weight of the washstand 100 is concentrated to the piston rod 103, so that the washstand 100 may be rocked during going up and down, and in a worse case, the deformation of the piston rod 103 may be caused.
In the meantime, the present applicant has suggested as Korean Patent Application No. 2002-0008351 (title; Hydraulic Height Adjuster) a technique which can allow the washstand to go up and down by providing a cylinder operable by water pressure at the bottom of the washstand, which is illustrated in FIGS. 2 and 3.
In FIGS. 2 and 3, the hydraulic height adjuster 200 comprises a cylinder 202 provided below a washstand 201, and a valve 205 for operating the cylinder 202. The cylinder 202 is coupled to the floor, and the piston rod 204 of the cylinder 202 is coupled to a bottom of the washstand 201.
Further, the valve 205 is sealed with packings 208, 210 in a housing 206 in which water holes 207 are formed, and comprises a bearing 216, a valve spool 212 in which a water conduit 213 is formed, and a valve cover 217 coupled to the top portion of the housing 206.
Furthermore, in order to operate the cylinder 202, a water supply pipe 218 for connecting a tap pipe and the valve 205, a water discharging pipe 219 for connecting the valve 205 and a drain pipe, and operational pipes 220, 221 for supplying water pressure controlled by the valve 205 to portions above and below a piston 203 in the cylinder 202 are provided.
In order to operate the hydraulic height adjuster 200, firstly, the water conduit 213 is made to coincide with the water supply pipe 218 and the upper operational pipe 220 or the lower operational pipe 221 by rotating a valve handle 215 coupled to a handle fastener 214 of the valve spool 212. Then, tap water is introduced into the operational pipes 220, 221 through the water conduit 213, water grooves 209, 211 of the packings 208, 210 and the water hole 207 of the housing 206, and supplied to the portions above and below the piston 203 in the cylinder 202, so that the washstand 201 coupled to the piston rod 204 can be made to go up and down.
As a result, a user can adjust the washstand 201 to a proper height through operation of the valve handle 215.
However, the hydraulic height adjuster 200 has a complex structure, the machining of the respective parts is difficult, and thus the price for a product is increased. Further, only when the water conduit 213 correctly coincides with the water supply pipe 218 and the operational pipes 220, 221, or the water discharging pipe 219 and the operational pipes 220, 221, the supply pressure of tap water gets into maximum, so that the washstand 201 can rapidly go up and down. However, there is a problem that the operation may be delayed because it is difficult to accomplish the accuracte coincidence.
That is, because the valve spool 212 has a spherical form, the machining thereof is very difficult, and several parts are necessary for the machining. Further, if the water conduit 213 does not correctly coincide, water may be leaked from an outer circumferential surface of the valve spool 212 or from portions at which several parts are coupled, so that the operation may be delayed or an erroneous operation may happen.